Hi all,

I have been having some problems with my Equinox (2008 3.4L AWD)

I have codes for Evap large leak on startup and EGR hi volt condition once the car gets nice and hot (after a 45-60 min drive in the winter) but disappears once the car fully cools down (overnight park)
The car is leaking coolant, but I can't tell from where. It is dripping off the starter but not from the thermostat housing or the upper rad hose. The oil and coolant look fine, but I have a little white smoke out of the tailpipe, more than normal for winter condensation. It also holds coolant in the system and "burps" it back in the jug from the bottom of the jug when I open the cap, but no air comes out of the bleeder on the water pump.
I have had some overheating issues over the past year, all fixed with new fans, new thermostat, and flushing the heater core.
So far, I have replaced the purge valve solenoid, EGR, down tube and gaskets, and a new rad jug cap to no avail.
It sounds like the lower manifold gasket is leaking? I know that it's rare, but I can't think of any other issues that would cause this.

Any help is appreciated, thanks.

 

This is normal. Don't do this! The coolant lid is designed to hold a certain amount of pressure (15 PSI in this case) to raise the boiling point of the coolant. When you remove the cap, you're releasing the pressure. This suddenly lowers the boiling point of the coolant, causing it to spontaneously boil all at once.

If you're sure you're seeing coolant on the starter, then obviously you have an external leak you need to find. That's a strange place to be seeing coolant to begin with on this engine. It's highly unlikely that your lower intake manifold gasket is leaking, but it's not impossible. Have you ruled out a weeping water pump? Hoses (including bypass/heater hoses)?

 

Sorry, should've specified that I only taken the cap off after it has cooled completely (after parking overnight or when the hose is cool to the touch) I haven't noticed any other leaks anywhere else. I smell burning coolant while it is running, so it is possible that the coolant is gone by the time I go looking. I don't see steam/smoke at all under the hood